CFTR Modulators Counteract F508del CFTR Functional Defects in a Pancreatic Epithelial Model of Cystic Fibrosis

Cystic fibrosis is a multisystem disorder caused by mutations in the CFTR gene that lead to impaired ion and fluid transport across secretory epithelia. Although the therapeutic impact of CFTR modulators has been extensively studied in airway epithelia, their efficacy in extra-pulmonary tissues, such as the pancreas, has been less explored. This study evaluated the effects of the CFTR modulators, VX770 (ivacaftor), VX661 (tezacaftor), and VX445 (elexacaftor), administered either individually or in combination, on CFPAC-1 cells, a pancreatic ductal epithelial cell line derived from a cystic fibrosis patient harboring the F508del CFTR mutation. The cells were cultured and differentiated onto porous supports, and a panel of functional parameters was assessed. These included transepithelial electrical conductance, fluid reabsorption, apical surface fluid pH, protein concentration, and microviscosity, the latter analyzed with multiple particle tracking. To simulate a pro-inflammatory micro-environment, the cells were preconditioned with lipopolysaccharide (LPS). Treatment with VX661 and VX445 resulted in significant improvement in epithelial function, with the triple combination producing the most pronounced rescue. Pro-inflammatory stimulation by LPS increased the production of cytokine IL6, IL-8, and IL-1β, as well as the protein content of the apical surface fluid. Despite the LPS pro-inflammatory stimulus, CFTR modulators preserved or slightly enhanced their efficacy in restoring CFTR-mediated ion and fluid transport. However, they did not reduce cytokine expression under pro-inflammatory conditions. Collectively, these findings show that CFTR modulators can restore critical aspects of cystic fibrosis pancreatic epithelial physiology in vitro, even under pro-inflammatory stress, supporting their potential relevance beyond the airway disease.